Answer:
-3
Step-by-step explanation:
Statistic significance requires that your sample be representative of the population, but I'm struggling with this because if the class is an elective then the answer would be: <span>No, it is not a valid inference because she asked all 22 students in her science class instead of taking a sample of the students in her school.
BUT if the class is required, as most science classes are, then it WOULD be a random sample of the school. So the last option would be correct.
My guess though is that the teacher is looking for answer B.
</span>
Answer:
12 in.
Step-by-step explanation:
Formula: a^2 + b^2 = c^2
This case: c^2 - a^2 = b^2
1) 15^2 + 9^2 = b^2
2) 225 - 81 = 144
3) 
= 12
Answer:
x = √30
Step-by-step explanation:
From small triangle BDC:
using Pythagorean theorem
CB² = BD² + DC²
x² = BD² + 3²
Fron triangles BDC and ADB.
ΔBDC has long leg BD and short leg DC.
ΔADB has long leg AD and shirt leg BD.
AD : BD = BD : DC
7 : BD = BD : 3
7*3 = BD*BD
BD² = 7*3 = 21
x² = BD² + 3² = 21+9 = 30
x² = 30
x = √30
